Humm
"We’ve known for years that Microsoft makes more money from Google’s Android than Google does itself"
There is multiple ways to see it. OS license sales maybe, but Google sales tablets and smartphones with a profit, not to mention the ad revenues. But as for hardware sales, we can also say that Google makes more money from their hardware operation than Microsoft will ever made :-P.
As for the other Android makers, HTC and Sony are a strange case. HTC makes great hardware but hit by lawsuits, bad management decisions and alienating their most loyal costumers by not updating flagships models were to much. If they colaborated more with outside developers they could have done better.
Sony...they do colaborate with external developers (freexperia, fxp) but releasing a barrage of high-end models every 6(?) months it's crazy, makes any costumer staying always in doubt when and what to buy. Why Samsung has a great success with the Notes? Software...
Just a note: I've been thinking about how one of the android makers could get away from Google and even if I'm of the opinion that it looks almost impossible for now, Samung, with their deep pockets maybe have a chance. A partnership with a cloud player (Akamai for example), a share of that 19bn that they spend in marketing to lure developers and revamp the hog that is TouchWiz, who knows?